Something New
by shockblanketsherlock
Summary: Another 'experiment' one-shot. Neither John nor Sherlock knows entirely what Sherlock is looking for, but maybe it's himself.


"This is the thirteenth experiment," growls Sherlock, nipping at the soft hollow above John's collarbone, pushing the open shirt back over his shoulders and pulling it roughly down the army medic's arms. "You remember the agreement."

John's fingers scrabble at the wallpaper either side of his hips. There are peppered lines of bullet holes in the wall; he digs his fingers into them for support. "I - yes." He bucks his hips involuntarily as Sherlock runs his tongue down the bare skin over his sternum.

"Your heart rate is escalating," Sherlock notes, his voice impassive. "Your skin is flushed."

There are rules, John tries to remind himself. Sherlock has made that abundantly clear a hundred times. No touching Sherlock, no talking to Sherlock, no ripping off Sherlock's bloody purple shirt…

He should be angry that Sherlock uses him in this way, takes advantage of the fact John so obviously adores him, but he never is. Until afterwards, but it's too late then.

"Your pupils are dilated," Sherlock observes. "Your temperature is rising. And your-"

"Yes," John bites out, praying his knees don't give way as Sherlock wraps slender fingers around each of his hips and begins to lick his way down the pale line of fuzz from his bellybutton to below his belt buckle. "You say these - these _things_ - every time, Sherlock, why are we-"

"An experiment has to be repeated multiple times with the same results for those results to be conclusive," Sherlock says, as if reciting from a textbook. He's on his knees now, sliding his hand up the inside of John's right thigh, pressing his palm against the heavy denim; there is a heat there that would undo any other man.

John hates this; hates himself for letting the other man's long fingers make him so damn hard. He can feel himself straining against his jeans, and can't help but reach a hand down to himself, suddenly desperate; he can't wait any longer, can't tolerate the tension. Sherlock always refuses to truly touch him _there_; he prefers to runs his hands and mouth _everywhere else_ until the retired medic comes, and John can't stand it. It's not _fair._

"No," says Sherlock, knocking John's hand away. "Don't touch yourself, it'll ruin it."

"But-"

"No." Sherlock glares at him. "Don't _interfere_, Watson, it's _dull_."

He hates how Sherlock always calls him Watson during these damn _experiments._ He's not even sure what they're _for; _Sherlock only tells him it's need-to-know information, and ignores all John's protests that he _does_ need to know. He sucks in a breath as the kneeling detective runs a hand down to his bare feet and strokes his left instep, tracing light fingers on his translucent skin. He wants so much to wind his fingers in the other man's tightly-curled hair, but he remembers trying that in the ninth experiment and Sherlock cancelling the entire thing abruptly, so instead he presses back against the wallpaper and draws in a long, shaky breath.

"Sherlock, I - I propose a variable to include in your research," he says, suddenly, as if they're inspecting the effects of corrosive acid on different brands of shoelaces.

All the same, it gets Sherlock's attention. He looks up. "What?"

"Try something new," suggests John, biting the inside of his cheek to stop himself from groaning as the detective's slim fingers press teasingly close to his erection. "Something you haven't tested before."

"A variable factor," Sherlock repeats, pressing his nose into John's thigh and deliberately inhaling the pheromones and that oh-so-familiar tang of saltiness that gives John's predicament away entirely. "Hmm."

"You can measure the difference," offers John, his heart hammering against his ribcage. It's not quite the kind of dirty talk he's used to whispering to women in the dark - but then he hasn't even _touched_ a woman that way since the night of the first experiment. Since he moved into Baker Street, really, but he's not prepared to admit that aloud. "Consider the physiological impact. The biochemical response."

"And what kind of variable could _you_ suggest that might possibly interest _me_?" Sherlock says. His voice is clinical, and yet something about his dry voice turns John on even more; makes him exude about twenty pheromones that Sherlock could probably identify standing on his head. John gulps.

"Youcouldkissme," he says, rushing the words.

He expects Sherlock to shake his head; say 'Dull,' and continue the pattern, removing his jeans with robotic efficiency and bruising him with little nips all the way up his calves and behind his knees again. He can feel precome lubricating him inside his boxers at the mere _memory_.

Instead, Sherlock straightens up slowly, staring down into John's face with unreadable eyes.

John shivers.

"You want me," Sherlock says, carefully, "to kiss you."

John manages to nod. His throat feels constricted.

"As part of the experiment."

"Yes…"

For the briefest of moments, John thinks Sherlock looks _frightened. _But that's impossible. Sherlock Holmes is a high-functioning sociopath who likes timing how long it takes to get his roommate off and playing with _real _knucklebones whilst waiting for someone to get murdered in a particularly inventive fashion. Sherlock Holmes does _not _get frightened of kissing his own test subject. No, he'll reject John for another reason entirely, probably because -

"Fine," says Sherlock abruptly. "Yes."

John blinks.

There is a moment of utter stillness, and then Sherlock's mouth covers his.

It's easier to say what the kiss _isn't_ than what it _is_. It's not sweet or virginal, but it's not hot or rough either. The closest John can come to it is _curious_. It's as though Sherlock is asking him a question - no, he realises, asking _himself _a question. Searching tongues taste sharp teeth; warm lips manipulate his own as he opens his eyes and almost comes simply from the intensity of Sherlock's expression.

And Sherlock isn't stopping, he realises.

John thrusts forward, feeling his denim-caged erection make contact with the base of Sherlock's cock, fully covered as it is by the man's expensive suit trousers. Sherlock splays strong fingers against John's wrists, stopping him from touching him, pressing him back against the wall without breaking their kiss. He can feel the hot, hard line of the taller man's erection against his stomach, and he moans against Sherlock's mouth at the friction between their bodies as John rocks against him desperately. He's not surprised that Sherlock doesn't thrust back, but it does startle him that he does nothing to stop him, simply pulling John's wrists above his head and aligning every plane of their bodies as he continues to kiss him. He doesn't seem to need to breathe; John has forgotten how.

"John," says Sherlock hoarsely, breath warm against John's cheek. "John, this isn't-"

John can't help it. He explodes inside his jeans, cock untouched, feeling the warmth spill through his lower body and engulf him as he tips his head back and surrenders to sweet oblivion.

He knows Sherlock feels it too, because he feels the detective's fingers tighten on his wrists as John breathes out _Sherlock _against his lips. He can feel his boxers sticking to his skin, but it doesn't matter; Sherlock called him _John _instead of _Watson _and for a whole moment he can believe this is more than an experiment.

"Sherlock," he wheezes. "That was - that was -"

He thinks, just for a second, that he sees something alive in Sherlock's blue-grey eyes, before the cold steel curtain snaps back into place.

"Interesting," Sherlock says, glancing at his wristwatch as he pulls away. "Six minutes and twenty-three seconds. That's three minutes four seconds less than last time."

John blinks. "Sherlock, listen to me -"

"I can't," Sherlock tells him, abruptly, eyes on his violin, on his blue scarf on its hook, on the unopened mail from three days ago that he dismissed as _dull. _He looks almost panicky, and for a moment, John can see the chink in the detective's armour as he stares down at him, lips slightly parted in shock. The curtain threatens to lift again; John sucks in a ragged breath, hoping…

But Sherlock is gone; the door to his bedroom slams shut with a _bang_. John is alone, naked to the waist in a soiled pair of boxers and jeans that are still uncomfortably tight - and yet, for the first time, he doesn't feel _used._


End file.
